Barometer



May 29, 1945. A A, RASPET Y y 2,377,182

l BAROMETER Filed sept. 4, 1944 NVENTOR. 9060.577- /769/57- -PatentedMay 29, 1945 Eo: STATES PATENT OFFICE.`

Kenyonlnstrument Co., Inc.,A Hunting-toni Sta-v tion, Long Island, N.Y., afcorporationr of" New York Applicatoirseptember 6 Claims.

This inventioareiates to ammeter's ana'simi; lar instruments. operatedby Variations of atmospheric pressure and has for its' objectH toprovide la. novel' and improved instrumentv of' this type.

Anotherobject ofthe invention is to provide a recording altimeter orbarograph' whichis highly sensitive `and accurate yet small andlight'enough to be carried'by a model airplaneV orglider with outmaterially increasing its weight.`

Another object' of' the invention isto provide an instrument of theabove type having'novel and improved details ofr construction and"features of operation; Various other objects and advantageswill beapparent as the nature of theiinvention is more fully disclosed'.

Although the novel leatureswhioh4 are characteristic of this inventionare set forth more in detail'in the claims" appended hereto; the natureand' scope oftheinventionv may be better 4, 1944', serial No; 552,615'(Cima-38e);

Ail() understoodby referring t0 thefollowingdescription,.taken inconnection with theraccompanying drawingfo'rming a' parvthereof, inwhich a specificembodiment has' been setforthfor purposes ofAillustration;

In the'idrawing:U

Fig. Il"` is" a" vertical4 sectionall View, taken on lineIi-I" ofFig; 2;showing anin'strument embodyingtheV invention;

Fig. 2 is horizontal sectional? view taken* on the line 2^-2of Fig: 1;

Fig: 3i is 'a' transverse lsectional f View; takenonline`3L-3'LofvFijg". 1, illustrating the mounting of there'cordingl'stylum and Fig.l 4l isa' perspective View of therec'ord anda. transparents'cale forreading same.- In the` following' description`certainA speci'c terms are used* for convenience inref'erring to the'various details" of the invention; These terms; however; are tobeinterpreted as broadly as 'the state of the' art will'permit.

The instrumentU shownin the `drawing includes a base I"having tabsZOrsecurin'g' same to'a support, a curved end`iwall'3', anda lighttransparent hoodforcover Il which ts over the base and has'notchesStinits'lower' edge-engaging pins B'on the; en'dfwall to secure the hoodin place.v

A* motor,` preferably `aV conventional stem-winding watch nfiovemeni;A1; ismountedon' lugs 8 securedvto r:tlie'baserlwith the stem 9 of thew-atch pointing forward so as to be engaged and turned by a suitable keywhich may be inserted through an opening I0 in the front end of the hood4.

The arbor I2, which normally carries the hour or minute hand in aconventional watch, has a Lil) flange I3formingj a seatfora thin disc orchart I`^4which has a central hole" I5 for centering same upon the'arbor. The arbor I2"is threaded for engagement with" a knurled nut IS`which clamps the dise I'4.t`o the flange I3? Accordingly, whenl the"wat'cli 'I has once' been wound", the ensuing'unwinding'movement causesthe'` disc I 4to rotate inH a' clockwisedirection' as viewed in Fig; 2;the time" required to eiectA a complete revolution of the disc beingeither twelve` hours "or A-one hour; depending 'upon which arbor" of theWatchjisjemployed, although itl will be understood thatthis timemay bevaried'if desire'd v In' the embodiment illustrated, the upper sur: faceof the disc I4 is polished, andibef'ore the instrument is used thissurfacev is completely coated with lampblack', ehalkorany othersuitablefugitive material of' distinctive colorwh'ich is easilyrubb'edj'off'jortetchedby'a pointedV object such' as". thel frictional stylushereinafter' described. y

The exhausted boxor bellowsI'I, of the type commonly employeddnself-registering barometers; is riveted or otherwise secured tothe endwall 3" of the: instrument; A pair of posts I8, likewise' secured totheend Wall 3 of the instrument; project' forward Lbeyond the 'bellows I1and carry a skeleton" frame I9 which is thusVv sus'- pended between thebellows and the motor T. The bellows. I'I and'thepostsA I8` arepreferably coinposedof the same material, or'o'f materials having thesame coefficient of "expansion, so' that expansionV orw contraction ofthe bellows" due to temp'eraturechan'ges will be accompaniedl by acorresponding change inthe position of the skeleton'fr'ame I9 carried byposts'l 8.

A flat metal band or Wire 20is drawn taut between the' upperand'loweredges of the skeleton frame I9 and has its endsweldedlorotherwise secured to said frame as shown'inV Figs. 1 and 3.

Theband'ZIVhasa central tubular portion 2 I; in-

` tegral therewith orsecured to the band inany tubular portion 2l ofband 20 as previously de-` scribed, is drawn taut toward the bellows I'Iwith suicient tension to twist the band axially out of its normal flatplane, and the end of wire 22 is then locked securely in the projection23 of bellows I'I byi pin 24 under this tension which maintains the band20 in its twisted condition.

In the embodiment illustrated, the tension whichr bellows I'I exertsupon wire 22 at normal atmospheric pressure is such that rthe flatintermediate portion of the band 20 carrying stylus arm 21 is twisted atright angles to the flat ends of the band which are anchored in skeletonframe I9, as shown in Figs. 1 and\ 3. This twisting of band 2i) gives ita torque which produces rotation or torsion of said band when thetension of wire 22 is eased by the expansion of bellows I'I.

It will thus be seen that when the bellows II is contracted, due to anincrease of atmospheric pressure, the wire 22 will be drawn tighter, ortoward the left as viewed in Fig. 1, thereby iurther twisting the band20 and correspondingly shifting the stylus arm 21. And when the bellowsIl expands, due to a decrease of atmospheric pressure, the tension onwire 22 will be slackened and the torque of band 20 will produce acorresponding untwisting of said band and a consequent shifting of thestylus arm 21 in a direction opposite to that previously mentioned.

When the altimeter is used, for example, in a model airplane or glider,the record disc I4, coated in the manner previously described, issecured in place beneath the stylus 28, and the motor 'i is wound up asalready explained. As the altimeter functions during the iiight thedeflections of the stylus will be traced or etched upon the record discI4, forming a track 29 thereon as illustrated diagrammatically in Fig.4.

At the conclusion of the flight the disc Illy is removed from theinstrument and the record interpreted by means of a transparent disc 30,containing a suitable scale y3l, which is superimposed upon the disc I4in the proper position to provide a reading in terms of altitude oratmospheric pressure, or angle of glide, as desired.

It will be understood, however, that the scale may be marked directly onthe disc I4, for example on an uncoated margin of said disc, if desired.

The instrument described above is extremely light and compact, yethighly sensitive, and at the same time more rugged and durable than manylarger altimeters and ,barographs Although a specific embodiment of theinvention has been shown for purposes of illustration it will beevidentl that the invention is capable of various modifications andadaptations without departing from the scope and spirit of the appendedclaims.`

What is claimed is:

1. An instrument of the type described, comprising a bellows responsiveto changes in atmospheric pressure, a taut ilexible band having acylindrical central portion perpendicular to the axis of said bellows, awire wrapped around the cylindrical portion of said band and secured tosaid bellows under a tension twisting said band in an axial direction, astylus carried by said band, and a movable chart cooperating with saidstylus.

2. An instrument of the type described, comprising a bellows responsiveto changes in atmospheric pressure, a frame adjacent said bellows, ataut flexible band having a cylindrical central portion and flat endportions secured to said frame in a plane perpendicular to the axis ofsaid bellows, a wire wrapped around the tubular portion of said band andsecured to said bellows under a tension twisting said band axially andcausing same to twist and untwist with the contraction and expansion ofsaid bellows, a stylus carried by said band, and a movable chartcooperating with said stylus.

3. An instrument of the type described, comprising a support, anexpansible bellows responsive to changes in atmospheric pressure havingone end mounted on said support and a movable end extending outwardlytherefrom, 'a xed frame adjacent said movable end, supporting membersfor said frame attached to said support, a taut ilexible band having acylindrical central portion and flat end portions secured to said framein a plane perpendicular to the axis ci said bellows, a wire wrappedaround the tubular portion of said band and secured to said movvable endof said bellows under a tension twisting said band axially and causingsame to twist and untwist with the contraction and expansion of saidbellows, and an indicator carried by said tubular portion.

4. An instrument of the type described, cornprising a bellows responsiveto changes in atmospheric pressure, a frame adjacent said bellows, ataut flexible band having a cylindrical central portion and flat endportions secured to said frame in a plane perpendicular to the axis ofsaid bellows, a wire wrapped around the tubular portion of said band andsecured to said bellows under a tension twisting said band axially andcausing same to twist and untwist with the contraction and expansion ofsaid bellows, and an indicator carried by said tubular portion.

5. An instrument or" the type described, comprising a bellows responsiveto changes in atmospheric pressure, a taut flexible band having acylindrical central portion perpendicular to the axis of said bellows, awire wrapped around the cylindrical portion of said band and secured tosaid bellows under a tension twisting said band longitudinally, a styluscarried by said band, and a rotatable disc cooperating with said stylusand having a coating of fugitive material adapted to be etched byfrictional contact with said stylus.

6. An instrument of the type described, comprising a bellows responsiveto changes in atmospheric pressure, a frame adjacent said bellows, ataut flexible band having a cylindrical central portion and ilat endportions secured to said frame in a plane perpendicular to the axis ofsaid bellows, a wire wrapped around the tubular portion of said band andsecured to said bellows under a tension twisting said bandlongitudinally and causing same to twist and untwist with thecontraction and expansion of said bellows, a stylus carried by saidband, and a rotatable record disc cooperating with said stylus landhaving a coating of fugitive material adapted to be etched by frictionalcontact with said stylus.

AUGUST RASPET.

